Unfortunately, this approach is skewed in favor of Windows because the sites that pay to be counted cater to such users. Conversely, Linux-oriented and other technical sites are unlikely to hire the services of companies such as Net Applications.

I'm all for the growing popularity of Linux, but I just took a look at the Wikimedia Traffic Analysis Report for last month. Of that 4.9%, 3.36% of that traffic came from Android devices, and adding up all the Desktop Linux versions you get about 1.35%. So while Linux is becoming more popular in general, Net Application's number is more accurate than yours for Linux on the desktop.... Sorry